Molecular sieve SSZ-108, its synthesis and use

ABSTRACT

A novel synthetic crystalline molecular sieve designated as SSZ-108 is disclosed. SSZ-108 may be synthesized using a structure directing agent comprising one or more of 1-butyl-1-methylpyrrolidinium cations and 1-butyl-1-methylpiperidinium cations. Molecular sieve SSZ-108 may be used in catalytic and sorptive processes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application Ser.No. 62/446,979, filed on Jan. 17, 2017, the disclosure of which is fullyincorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a novel synthetic crystalline molecular sievedesignated SSZ-108, its synthesis, and its use in sorption and catalyticprocesses.

BACKGROUND

Molecular sieve materials, both natural and synthetic, have beendemonstrated in the past to be useful as adsorbents and to havecatalytic properties for various types of organic conversion reactions.Certain molecular sieves, such as zeolites, aluminophosphates, andmesoporous materials, are ordered, porous crystalline materials having adefinite crystalline structure as determined by X-ray diffraction.Within the crystalline molecular sieve material there are a large numberof cavities which may be interconnected by a number of channels orpores. These cavities and pores are uniform in size within a specificmolecular sieve material. Because the dimensions of these pores are suchas to accept for adsorption molecules of certain dimensions whilerejecting those of larger dimensions, these materials have come to beknown as “molecular sieves” and are utilized in a variety of industrialprocesses.

Although many different crystalline molecular sieves have beendiscovered, there is a continuing need for new molecular sieves withdesirable properties for gas separation and drying, chemical conversionreactions, and other applications.

According to the present disclosure, a new molecular sieve, designatedSSZ-108 and having a unique X-ray diffraction pattern, has now beensynthesized using one or more of 1-butyl-1-methylpyrrolidinium cationsand 1-butyl-1-methylpiperidinium cations as a structure directing agent.

SUMMARY

In one aspect, there is provided a molecular sieve having, in itsas-synthesized form, an X-ray diffraction pattern including the peakslisted in Table 2.

In its as-synthesized and anhydrous form, the molecular sieve has achemical composition comprising the following molar relationship:

Broad Exemplary SiO₂/Al₂O₃ 5 to 25 5 to 15 Q/SiO₂ >0 to 0.1 >0 to 0.1M/SiO₂ >0 to 0.1 >0 to 0.1wherein Q comprises one or more of 1-butyl-1-methylpyrrolidinium cationsand 1-butyl-1-methylpiperidinium cations; and M is a Group 1 or Group 2metal.

In another aspect, there is provided a molecular sieve having, in itscalcined form, an X-ray diffraction pattern including the peaks listedin Table 3.

In its calcined form, the molecular sieve has a chemical compositioncomprising the following molar relationship:Al₂O₃:(n)SiO₂wherein n has a value of from 5 to 25.

In a further aspect, there is provided a method of synthesizing themolecular sieve described herein, the method comprising (a) preparing areaction mixture comprising: (1) a source of silicon oxide; (2) a sourceof aluminum oxide; (3) a source of a Group 1 or Group 2 metal; (4) astructure directing agent comprising one or more of1-butyl-1-methylpyrrolidinium cations and 1-butyl-1-methylpiperidiniumcations; (5) hydroxide ions; and (6) water; and (b) subjecting thereaction mixture to crystallization conditions sufficient to formcrystals of the molecular sieve.

In yet a further aspect, there is provided an organic compoundconversion process comprising contacting an organic compound underorganic compound conversion conditions with a catalyst comprising anactive form of the molecular sieve described herein.

In still yet a further aspect, there is provided a process ofselectively reducing nitrogen oxides (NO_(x)) comprising contacting agas stream containing nitrogen oxides, with a catalyst comprising themolecular sieve described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the powder X-ray diffraction (XRD) pattern of theas-synthesized molecular sieve of Example 1.

FIG. 2 is a Scanning Electron Micrograph (SEM) image of theas-synthesized molecular sieve of Example 1.

FIG. 3 shows the powder XRD pattern of the calcined molecular sieve ofExample 6.

DETAILED DESCRIPTION Introduction

The term “as-synthesized” is employed herein to refer to a molecularsieve in its form after crystallization, prior to removal of thestructure directing agent.

The term “anhydrous” is employed herein to refer to a molecular sievesubstantially devoid of both physically adsorbed and chemically adsorbedwater.

As used herein, the numbering scheme for the Periodic Table Groups is asdisclosed in Chem. Eng. News 1985, 63(5), 26-27.

Reaction Mixture

In general, the present molecular sieve is synthesized by: (a) preparinga reaction mixture comprising (1) a source of silicon oxide; (2) asource of aluminum oxide; (3) a source of a Group 1 or Group 2 metal(M); (4) a structure directing agent (Q) comprising one or more of1-butyl-1-methylpyrrolidinium cations and 1-butyl-1-methylpiperidiniumcations; (5) hydroxide ions; and (6) water; and (b) subjecting thereaction mixture to crystallization conditions sufficient to formcrystals of the molecular sieve.

The composition of the reaction mixture from which the molecular sieveis formed, in terms of molar ratios, is identified in Table 1 below:

TABLE 1 Reactants Broad Exemplary SiO₂/Al₂O₃ 10 to 100 15 to 80 M/SiO₂0.05 to 1.00 0.10 to 0.60 Q/SiO₂ 0.05 to 0.50 0.10 to 0.35 OH/SiO₂ 0.10to 1.00 0.40 to 0.80 H₂O/SiO₂ 10 to 60 15 to 40

Suitable sources of silicon oxide silicon oxide include colloidalsilica, fumed silica, precipitated silica, alkali metal silicates andtetraalkyl orthosilicates.

Suitable sources of aluminum oxide include hydrated alumina andwater-soluble aluminum salts (e.g., aluminum nitrate).

Combined sources of silicon oxide and aluminum oxide can additionally oralternatively be used and can include aluminosilicate zeolites (e.g.,zeolite Y) and clays or treated clays (e.g., metakaolin).

The structure directing agent (Q) comprises one or more of1-butyl-1-methylpyrrolidinium cations and 1-butyl-1-methylpiperidiniumcations, represented by the following structures (1) and (2),respectively:

Suitable sources of Q are the hydroxides, chlorides, bromides, and/orother salts of the quaternary ammonium compounds.

Examples of suitable Group 1 or Group 2 metals (M) include sodium,potassium and calcium, with sodium being preferred. The metal isgenerally present in the reaction mixture as the hydroxide.

The reaction mixture may contain seeds of a molecular sieve material,such as SSZ-108 crystals from a previous synthesis, in an amount of from0.01 to 10,000 ppm by weight (e.g., 100 to 5000 ppm by weight) of thereaction mixture.

For each embodiment described herein, the molecular sieve reactionmixture can be supplied by more than one source. Also, two or morereaction components can be provided by one source.

The reaction mixture can be prepared either batch wise or continuously.Crystal size, morphology and crystallization time of the molecular sievedescribed herein can vary with the nature of the reaction mixture andthe crystallization conditions.

Crystallization and Post-Synthesis Treatment

Crystallization of the molecular sieve from the above reaction mixturecan be carried out under either static, tumbled or stirred conditions ina suitable reactor vessel, such as for example polypropylene jars orTeflon-lined or stainless steel autoclaves, at a temperature of from120° C. to 200° C. for a time sufficient for crystallization to occur atthe temperature used, e.g., from 1 to 15 days. Crystallization isusually carried out in a closed system under autogenous pressure.

Once the molecular sieve crystals have formed, the solid product isrecovered from the reaction mixture by standard mechanical separationtechniques such as centrifugation or filtration. The crystals arewater-washed and then dried to obtain the as-synthesized molecular sievecrystals. The drying step is typically performed at a temperature ofless than 200° C.

As a result of the crystallization process, the recovered crystallinemolecular sieve product contains within its pore structure at least aportion of the structure directing agent used in the synthesis.

The molecular sieve described herein may be subjected to subsequenttreatment to remove part or all of the structure directing agent used inits synthesis. This can be conveniently effected by thermal treatment inwhich the as-synthesized material can be heated at a temperature of atleast 370° C. for at least 1 minute and not longer than 24 hours. Thethermal treatment can be performed at a temperature up to 925° C. Whilesub-atmospheric and/or super-atmospheric pressures can be employed forthe thermal treatment, atmospheric pressure may typically be desired forreasons of convenience. Additionally or alternatively, the structuredirecting agent can be removed by treatment with ozone (see, e.g., A. N.Parikh et al., Micropor. Mesopor. Mater. 2004, 76, 17-22).

The original Group 1 or 2 metal cations (e.g., Na⁺) in theas-synthesized molecular sieve can be replaced in accordance withtechniques well known in the art by ion exchange with other cations.Preferred replacing cations include metal ions, hydrogen ions, hydrogenprecursor (e.g., ammonium) ions and mixtures thereof. Particularlypreferred replacing cations are those which tailor the catalyticactivity for certain chemical conversion reactions. These includehydrogen, rare earth metals and metals of Groups 2 to 15 of the PeriodicTable of the Elements.

It may be desirable to incorporate the present molecular sieve withanother component resistant to the temperatures and other conditionsemployed in organic conversion processes. Such components can includeactive and inactive materials and synthetic or naturally occurringzeolites, as well as inorganic materials such as clays, silica, and/ormetal oxides such as alumina. The latter may be either naturallyoccurring or in the form of gelatinous precipitates or gels includingmixtures of silica and other metal oxides. Use of a material inconjunction with SSZ-108 (i.e., combined therewith or present duringsynthesis of the crystalline material, which can be in its active state)can tend to change the level of conversion and/or selectivity of thecatalyst in certain chemical conversion processes. Inactive materialscan suitably serve as diluents, e.g., to control the amount ofconversion in a given process, so that products can be obtained in aneconomic and orderly manner, such as without employing other means forcontrolling the rate of reaction. These materials may be incorporatedinto naturally occurring clays (e.g., bentonite and/or kaolin) toimprove the crush strength of the catalyst under commercial operatingconditions. These materials (i.e., clays, oxides, etc.) can function asbinders for the catalyst. It can be desirable to provide a catalysthaving good crush strength, because, in commercial use, it can bedesirable to prevent/limit the catalyst from breaking down intopowder-like materials (fines). These clay and/or oxide binders can beemployed, for example, solely to improve the crush strength of thecatalyst.

Naturally occurring clays that can be composited with SSZ-108 caninclude the montmorillonite and kaolin families, which families includethe sub-bentonites, and the kaolins commonly known as Dixie, McNamee,Georgia and Florida clays, as well as others in which the main mineralconstituent is halloysite, kaolinite, dickite, nacrite, or anauxite.Such clays can be used in the raw state (as originally mined) and/orinitially subjected to calcination, acid treatment, and/or chemicalmodification. Binders useful for compositing with SSZ-108 canadditionally or alternately include inorganic oxides, such as silica,zirconia, titania, magnesia, beryllia, alumina, and mixtures thereof.

Additionally or alternatively to the foregoing materials, as desired,SSZ-108 can be composited with a porous matrix material, such assilica-alumina, silica-magnesia, silica-zirconia, silica-thoria,silica-beryllia, silica-titania, as well as ternary compositions such assilica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia,silica-magnesia-zirconia, and mixtures thereof.

The relative proportions of SSZ-108 and inorganic oxide matrix may varywidely, with the SSZ-108 content typically ranging from 1 to 90 wt. %(e.g., 2 to 80 wt. %), based on the total composite weight.

Characterization of the Molecular Sieve

In its as-synthesized and anhydrous form, the present molecular sievehas a chemical composition comprising the following molar relationship:

Broad Exemplary SiO₂/Al₂O₃ 5 to 25 5 to 15 Q/SiO₂ >0 to 0.1 >0 to 0.1M/SiO₂ >0 to 0.1 >0 to 0.1wherein compositional variables Q and M are as described herein above.

It should be noted that the as-synthesized form of the present molecularsieve may have molar ratios different from the molar ratios of reactantsof the reaction mixture used to prepare the as-synthesized form. Thisresult may occur due to incomplete incorporation of 100% of thereactants of the reaction mixture into the crystals formed (from thereaction mixture).

In its calcined form, the present molecular sieve has a chemicalcomposition comprising the following molar relationship:Al₂O₃:(n)SiO₂wherein n has a value of from 5 to 25 (e.g., 5 to 20, or 5 to 15).

The novel molecular sieve structure SSZ-108 is characterized by a powderX-ray diffraction pattern, which in the as-synthesized form of themolecular sieve, includes at least the lines listed in Table 2 below andwhich, in the calcined form of the molecular sieve, includes at leastthe peaks listed in Table 3 below.

TABLE 2 Characteristic Peaks for As-Synthesized SSZ-108 2-Theta^((a))d-Spacing, nm Relative Intensity^((b)) Peak Broadening^((c)) 7.46 1.184M B 9.02 0.980 M B 11.24 0.787 W B 12.90 0.686 M Sh 15.25 0.581 W B15.86 0.558 W Sh 17.72 0.500 VS Sh 20.43 0.434 VS B 21.58 0.412 VS B22.44 0.396 W Sh 25.97 0.343 S Sh 27.62 0.323 W B 30.45 0.293 VS B 31.230.286 S B 33.85 0.265 W Sh 34.59 0.259 M Sh ^((a))±0.20 ^((b))The powderXRD patterns provided are based on a relative intensity scale in whichthe strongest line in the XRD pattern is assigned a value of 100: W =weak (>0 to ≤20); M = medium (>20 to ≤40); S = strong (>40 to ≤60); VS =very strong (>60 to ≤100). ^((c))Peak broadening is characterized by theFull-Width at Half Maximum (FWHM) of the XRD peak. Based on the FWHMvalues, the peaks are classified as: Sh = sharp (≤2 × smallest FWHM); B= broad (>2 × smallest FWHM).

TABLE 3 Characteristic Peaks for Calcined SSZ-108 2-Theta^((a))d-Spacing, nm Relative Intensity^((b)) Peak Broadening^((c)) 7.51 1.176W B 9.11 0.971 M B 12.90 0.686 S Sh 15.92 0.556 W Sh 17.74 0.500 S Sh20.43 0.434 VS B 21.60 0.411 VS B 26.03 0.342 S Sh 27.70 0.322 W B 30.530.293 VS B 31.38 0.285 S B 34.65 0.259 W Sh ^((a))±0.20 ^((b))The powderXRD patterns provided are based on a relative intensity scale which thestrongest line in the XRD pattern is assigned a value of 100: W = weak(>0 to ≤20); M = medium (>20 to ≤40); S = strong (>40 to ≤60); VS = verystrong (>60 to ≤100). ^((c))Peak broadening is characterized by theFull-Width at Half Maximum (FWHM) of the XRD peak. Based on the FWHMvalues, the peaks are classified as: Sh = sharp (≤2 × smallest FWHM); B= broad (>2 × smallest FWHM).

The powder X-ray diffraction patterns presented herein were collected bystandard techniques. The radiation was CuKα radiation. The peak heightsand the positions, as a function of 2θ where θ is the Bragg angle, wereread from the relative intensities of the peaks (adjusting forbackground), and d, the interplanar spacing corresponding to therecorded lines, can be calculated.

Minor variations in the diffraction pattern can result from variationsin the mole ratios of the framework species of the particular sample dueto changes in lattice constants. In addition, sufficiently disorderedmaterials and/or small crystals will affect the shape and intensity ofpeaks, leading to significant peak broadening. Minor variations in thediffraction pattern can also result from variations in the organiccompound used in the preparation. Calcination can also cause minorshifts in the XRD pattern. Notwithstanding these minor perturbations,the basic crystal lattice structure remains unchanged.

Sorption and Catalysis

The present molecular sieve may be used as a sorbent or a catalyst for avariety of chemical reactions. The present molecular sieve isparticularly suited for use as a catalyst for organic conversionprocesses and for the reduction of nitrogen oxides in a gas stream.Examples of organic conversion processes which may be catalyzed by thepresent molecular sieve include, but are not limited to, animating loweralcohols and converting organic oxygenates to one or more olefins. Suchreactions may be catalyzed by contacting the respective feedstock with acatalyst comprising SSZ-108 under conditions sufficient to affect thenamed transformation.

The present molecular sieve may be used in the catalytic conversion oforganic oxygenates to one or more olefins, particularly ethylene andpropylene. The term “organic oxygenates” is defined herein to includealiphatic alcohols, ethers, carbonyl compounds (e.g., aldehydes,ketones, carboxylic acids, carbonates, and the like), and also compoundscontaining hetero-atoms, such as, halides, mercaptans, sulfides, amines,and mixtures thereof. The aliphatic moiety normally contains from 1 to10 carbon atoms (e.g., 1 to 4 carbon atoms).

Representative organic oxygenates include lower straight chain orbranched aliphatic alcohols, their unsaturated counterparts, and theirnitrogen, halogen, and sulfur analogs. Examples of suitable organicoxygenate compounds include methanol; ethanol; n-propanol; isopropanol;C₄ to C₁₀ alcohols; methyl ethyl ether; dimethyl ether; diethyl ether;diisopropyl ether; formaldehyde; dimethyl carbonate; acetone; aceticacid; n-alkyl amines, n-alkyl halides, n-alkyl sulfides having n-alkylgroups in a range of from 3 to 10 carbon atoms; and mixtures thereof.Particularly suitable oxygenate compounds are methanol, dimethyl ether,or combinations thereof, especially methanol.

In the present oxygenate conversion process, a feedstock comprising anorganic oxygenate, optionally, with one or more diluents, is contactedin the vapor phase in a reaction zone with a catalyst comprising thepresent molecular sieve at effective process conditions so as to producethe desired olefins. Alternatively, the process may be carried out in aliquid or a mixed vapor/liquid phase. When the process is carried out inthe liquid phase or a mixed vapor/liquid phase, different conversionrates and selectivities of feedstock-to-product may result dependingupon the catalyst and the reaction conditions.

When present, the diluent is generally non-reactive to the feedstock ormolecular sieve catalyst composition and is typically used to reduce theconcentration of the oxygenate in the feedstock. Non-limiting examplesof suitable diluents include helium, argon, nitrogen, carbon monoxide,carbon dioxide, water, essentially non-reactive paraffins (especiallyalkanes such as methane, ethane, and propane), essentially non-reactivearomatic compounds, and mixtures thereof. The most preferred diluentsare water and nitrogen, with water being particularly preferred.Diluent(s) may comprise from 1 to 99 mol % of the total feed mixture.

The temperature employed in the oxygenate conversion process may varyover a wide range, such as from 200° C. to 1000° C. (e.g., 250° C. to800° C., 300° C. to 650° C., or 400° C. to 600° C.).

Light olefin products will form, although not necessarily in optimumamounts, at a wide range of pressures, including autogenous pressuresand pressures in the range of from 0.1 kPa to 10 MPa (e.g., 7 kPa to 5MPa, or 50 kPa to 1 MPa). The foregoing pressures are exclusive ofdiluent, if any is present, and refer to the partial pressure of thefeedstock as it relates to oxygenate compounds and/or mixtures thereof.Lower and upper extremes of pressure may adversely affect selectivity,conversion, coking rate, and/or reaction rate; however, light olefinssuch as ethylene and/or propylene may still may form.

The oxygenate conversion process should be continued for a period oftime sufficient to produce the desired olefin products. The reactiontime may vary from tenths of seconds to a number of hours. The reactiontime is largely determined by the reaction temperature, the pressure,the catalyst selected, the weight hourly space velocity, the phase(liquid or vapor), and the selected process design characteristics.

A wide range of weight hourly space velocities (WHSV) can be used in thepresent oxygenate conversion process. WHSV is defined as weight of feed(excluding diluent) per hour per weight of a total reaction volume ofmolecular sieve catalyst (excluding inerts and/or fillers). The WHSVgenerally may be in the range of from 0.01 to 500 h⁻¹ (e.g., 0.5 to 300h⁻¹, or 1 to 200 h⁻¹).

The present molecular sieve may be used in the selective catalyticreduction (SCR) of nitrogen oxides. In this process, a gas streamcomprising nitrogen oxides (NO_(x)) is selectively reduced in thepresence of a reductant and a catalyst comprising the present molecularsieve. The nitrogen oxides (principally NO and NO₂) are reduced to N₂while the reductant is oxidized. When ammonia is the reductant, N₂ isalso an oxidation product. Ideally, the only reaction products are waterand N₂, although some NH₃ is usually oxidized with air to NO or N₂O.

To promote the catalytic activity, one more transition metals may beincorporated into the molecular sieve support. Any suitable transitionmetal may be selected. Transition metals particularly effective for useduring selective catalytic reduction include one or more of Cr, Mn, Fe,Co, Ce, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Re, Ir, and Pt. In one embodiment,the transition metal is selected from Fe and Cu. In an exemplaryembodiment, the transition metal is Cu. Any suitable and effectiveamount of transition metal may be used in the catalyst. The total amountof the transition metal(s) that may be included in the molecular sievemay be from 0.01 to 20 wt. % (e.g., 0.1 to 10 wt. %, 0.5 to 5 wt. %, or1 to 2.5 wt. %) based on the total weight of the molecular sievesupport.

The molecular sieve catalyst may be used in any suitable form. Forexample, the molecular sieve catalyst may be used in powder form, asextrudates, as pellets, or in any other suitable form.

The molecular sieve catalyst for use in the reduction of nitrogen oxidesmay be coated on a suitable substrate monolith or can be formed asextruded-type catalysts, but is preferably used in a catalyst coating.In one embodiment, the molecular sieve catalyst is coated on aflow-through monolith substrate (i.e., a honeycomb monolithic catalystsupport structure with many small, parallel channels running axiallythrough the entire part) or filter monolith substrate, such as awall-flow filter, etc. The molecular sieve catalyst for use herein maybe coated (e.g., as a washcoat component) on a suitable monolithsubstrate, such as a metal or ceramic flow through monolith substrate ora filtering substrate, such as a wall-flow filter or sintered metal orpartial filter. Alternatively, the molecular sieve may be synthesizeddirectly onto the substrate and/or may be formed into an extruded-typeflow through catalyst.

The gas stream comprising nitrogen oxides may contain one or more of NO,NO₂, and N₂O in addition to other non-NO_(x) gases such as N₂, O₂, CO,CO₂, SO₂, HCl and H₂O. The gas stream may contain from 1 to 10,000 ppm(e.g., 10 to 1,000 ppm, or 50 to 500 ppm) of NO.

The gas stream comprising nitrogen oxides may be an exhaust gas derivedfrom a combustion process, such as from an internal combustion engine(whether mobile or stationary), a gas turbine or coal or oil firedplants.

The reductant can be a nitrogen compound or a short-chain (e.g., C₁ toC₈) hydrocarbon. Preferably, the reductant is a nitrogen compound.Suitable nitrogen compounds include ammonia, hydrazine, and ammoniaprecursors (e.g., urea, ammonium carbonate, ammonium carbamate, ammoniumhydrogen carbonate, and ammonium formate).

The gas stream comprising nitrogen oxides can contact the catalyst at agas hourly space velocity of from 5000 to 500,000 h⁻¹ (e.g., 10,000 to200,000 h⁻¹).

The reduction of nitrogen oxides may be carried out at a temperaturewithin the range of 100° C. to 650° C. (e.g., 250° C. to 600° C.).

The reduction of nitrogen oxides may be carried out in the presence ofoxygen or in the absence of oxygen.

EXAMPLES

The following illustrative examples are intended to be non-limiting.

Example 1

4.62 g of deionized water, 1.93 g of a 50% NaOH solution, 14.14 g of a16.33% 1-butyl-1-methylpyrrolidinium hydroxide solution and 3.00 g ofCBV760 Y-zeolite powder (Zeolyst International, SiO₂/Al₂O₃ molarratio=60) were mixed together in a Teflon liner. The resulting gel wasstirred until it became homogeneous. The liner was then capped andplaced within a Parr steel autoclave reactor. The autoclave was thenplaced in an oven and the heated at 135° C. for 4 days. The solidproducts were recovered by centrifugation, washed with deionized waterand dried at 95° C.

Powder XRD of the as-synthesized product gave the pattern indicated inFIG. 1 and showed the product to be a pure form of a new phase,designated SSZ-108. A SEM image of the as-synthesized product is shownin FIG. 2 indicating a uniform field of crystals.

The as-synthesized product had a SiO₂/Al₂O₃ molar ratio of 8.82, asdetermined by ICP elemental analysis.

Example 2

27.89 g of deionized water, 7.09 g of a 50% NaOH solution, 39.27 g of a16.33% 1-butyl-1-methylpyrrolidinium hydroxide solution and 10.00 g ofCBV760 Y-zeolite powder (Zeolyst International, SiO₂/Al₂O₃ molarratio=60) were mixed together in a Teflon liner. The resulting gel wasstirred until it became homogeneous. The liner was then capped andplaced within a Parr steel autoclave reactor. The autoclave was thenplaced in an oven and the heated at 135° C. for 4 days. The solidproducts were recovered by centrifugation, washed with deionized waterand dried at 95° C.

Powder XRD showed the product to be pure SSZ-108.

The as-synthesized product had a SiO₂/Al₂O₃ molar ratio of 8.24, asdetermined by ICP elemental analysis.

Example 3

8.37 g of deionized water, 2.32 g of a 50% NaOH solution, 9.42 g of a16.33% 1-butyl-1-methylpyrrolidinium hydroxide and 3.00 g of CBV720Y-zeolite powder (Zeolyst International, SiO₂/Al₂O₃ molar ratio=30) weremixed together in a Teflon liner. The resulting gel was stirred until itbecame homogeneous. The liner was then capped and placed within a Parrsteel autoclave reactor. The autoclave was then placed in an oven andthe heated at 135° C. for 4 days. The solid products were recovered bycentrifugation, washed with deionized water and dried at 95° C.

Powder XRD showed the product to be a mixture of SSZ-108 and ANAframework type zeolite.

Example 4

32.74 g of deionized water, 6.44 g of a 50% NaOH solution, 27.66 g of a20.19% 1-butyl-1-methylpiperidinium hydroxide solution and 10.00 g ofCBV760 Y-zeolite powder (Zeolyst International, SiO₂/Al₂O₃ molarratio=60) were mixed together in a Teflon liner. The resulting gel wasstirred until it became homogeneous. The liner was then capped andplaced within a Parr steel autoclave reactor. The autoclave was thenplaced in an oven and the heated at 135° C. for 5 days. The solidproducts were recovered by centrifugation, washed with deionized waterand dried at 95° C.

Powder XRD showed the product to be pure SSZ-108.

The as-synthesized product had a SiO₂/Al₂O₃ mole ratio of 7.95, asdetermined by ICP elemental analysis.

Example 5

9.82 g of deionized water, 1.93 g of a 50% NaOH solution, 8.30 g of a20.19% 1-butyl-1-methylpiperidinium hydroxide solution and 3.00 g ofCBV780 Y-zeolite powder (Zeolyst International, SiO₂/Al₂O₃ molarratio=80) were mixed together in a Teflon liner. The resulting gel wasstirred until it became homogeneous. The liner was then capped andplaced within a Parr steel autoclave reactor. The autoclave was thenplaced in an oven and the heated at 135° C. for 4 days. The solidproducts were recovered by centrifugation, washed with deionized waterand dried at 95° C.

Powder XRD showed the product to be a mixture of SSZ-108 and ANAframework type zeolite.

Example 6

The as-synthesized molecular sieve product of Example 1 was calcinedinside a muffle furnace under a flow of air heated to 540° C. at a rateof 1° C./minute and held at 540° C. for 5 hours, cooled and thenanalyzed by powder XRD.

Powder XRD of the calcined product gave the pattern indicated in FIG. 3and showed the material to be stable after calcination to remove theorganic structure directing agent.

Example 7

The calcined molecular sieve material of Example 6 was treated with 10mL (per g of molecular sieve) of a 1N ammonium nitrate solution at 90°C. for 2 hours. The mixture was cooled, the solvent decanted off and thesame process repeated.

After drying, the product (NH₄—SSZ-108) was subjected to microporevolume analysis using N₂ an adsorbate and via the B.E.T. method. Themolecular sieve had a micropore volume of 0.15 cm³/g.

The invention claimed is:
 1. A molecular sieve having, in itsas-synthesized form, an X-ray diffraction pattern including the peakslisted in the following Table: 2-Theta d-Spacing, nm Relative IntensityPeak Broadening  7.46 ± 0.20 1.184 M B  9.02 ± 0.20 0.980 M B 11.24 ±0.20 0.787 W B 12.90 ± 0.20 0.686 M Sh 15.25 ± 0.20 0.581 W B 15.86 ±0.20 0.558 W Sh 17.72 ± 0.20 0.500 VS Sh 20.43 ± 0.20 0.434 VS B 21.58 ±0.20 0.412 VS B 22.44 ± 0.20 0.396 W Sh 25.97 ± 0.20 0.343 S Sh 27.62 ±0.20 0.323 W B 30.45 ± 0.20 0.293 VS B 31.23 ± 0.20 0.286 S B 33.85 ±0.20 0.265 W Sh 34.59 ± 0.20 0.259 M Sh.


2. The molecular sieve of claim 1, and having a composition comprisingthe molar relationship: SiO₂/Al₂O₃ 5 to 25 Q/SiO₂ >0 to 0.1 M/SiO₂ >0 to0.1

wherein Q comprises one or more of 1-butyl-1-methylpyrrolidinium cationsand 1-butyl-1-methylpiperidinium cations; and M is a Group 1 or Group 2metal.
 3. The molecular sieve of claim 1, and having a compositioncomprising the molar relationship: SiO₂/Al₂O₃ 5 to 15 Q/SiO₂ >0 to 0.1M/SiO₂ >0 to 0.1

wherein Q comprises one or more of 1-butyl-1-methylpyrrolidinium cationsand 1-butyl-1-methylpiperidinium cations; and M is a Group 1 or Group 2metal.
 4. A method of synthesizing the molecular sieve of claim 1, themethod comprising: (a) preparing a reaction mixture comprising: (1) asource of silicon oxide; (2) a source of aluminum oxide; (3) a source ofa Group 1 or Group 2 metal (M); (4) a structure directing agent (Q)comprising one or more of 1-butyl-1-methylpyrrolidinium cations and1-butyl-1-methylpiperidinium cations; (5) hydroxide ions; and (6) water;and (b) subjecting the reaction mixture to crystallization conditionssufficient to form crystals of the molecular sieve.
 5. The method ofclaim 4, wherein the reaction mixture has a composition, in terms ofmolar ratios, as follows: SiO₂/Al₂O₃ 10 to 100 M/SiO₂ 0.05 to 1.00Q/SiO₂ 0.05 to 0.50 OH/SiO₂ 0.10 to 1.00 H₂O/SiO₂ 10 to
 60.


6. The method of claim 4, wherein the reaction mixture has acomposition, in terms of mole ratios, as follows: SiO₂/Al₂O₃ 15 to 80M/SiO₂ 0.10 to 0.60 Q/SiO₂ 0.10 to 0.35 OH/SiO₂ 0.40 to 0.80 H₂O/SiO₂ 15to
 40.


7. The method of claim 4, wherein the crystallization conditions includea temperature of from 120° C. to 200° C.
 8. A molecular sieve having, inits calcined form, an X-ray diffraction pattern including the peakslisted in the following Table: 2-Theta d-Spacing, nm Relative IntensityPeak Broadening  7.51 ± 0.20 1.176 W B  9.11 ± 0.20 0.971 M B 12.90 ±0.20 0.686 S Sh 15.92 ± 0.20 0.556 W Sh 17.74 ± 0.20 0.500 S Sh 20.43 ±0.20 0.434 VS B 21.60 ± 0.20 0.411 VS B 26.03 ± 0.20 0.342 S Sh 27.70 ±0.20 0.322 W B 30.53 ± 0.20 0.293 VS B 31.38 ± 0.20 0.285 S B 34.65 ±0.20 0.259 W Sh.


9. The molecular sieve of claim 8, and having a composition comprisingthe molar relationship:Al₂O₃:(n)SiO₂ wherein n has a value of from 5 to
 25. 10. An organiccompound conversion process comprising contacting an organic compoundunder organic compound conversion conditions with a catalyst comprisingthe molecular sieve of claim
 8. 11. The organic compound conversionprocess of claim 10, wherein the organic compound comprises an organicoxygenate compound and the organic compound conversion process convertsthe organic oxygenate compound to a product comprising olefins.
 12. Theorganic compound conversion process of claim 11, wherein the organicoxygenate compound comprises methanol, dimethyl ether, or a combinationthereof and the olefins comprise ethylene, propylene, or a combinationthereof.
 13. A process of selectively reducing nitrogen oxides (NO_(x)),comprising contacting a gas stream containing nitrogen oxides with acatalyst comprising the molecular sieve of claim
 8. 14. The process ofclaim 13, wherein the catalyst further comprises a transition metalselected from or more of Cr, Mn, Fe, Co, Ce, Ni, Cu, Mo, Ru, Rh, Pd, Ag,Re, Ir, and Pt.
 15. The process of claim 14, wherein the transitionmetal is present in an amount of 0.1 to 10 wt. %, based on the totalweight of the molecular sieve.